Sensors are used in connection with measuring any number of characteristics of objects and the environment around such objects. The complexity of sensors can vary from the most simple sensor, such as a bubble level, to the most complex digital signal processor-based sensors. The cost of a sensor is usually directly proportional to the complexity of the sensor.
The typical objective of using sensors is to detect a certain parameter of interest at the lowest possible cost. While some parameters require the use of complex sensors to be detected accurately, other parameters lend themselves to being detected with less costly sensors. Often times, the key to developing a cost efficient sensor is to leverage features of the object or system being monitored.
Sensors are often used in ventilators. Ventilators are used to provide a breathing gas to a patient who is unable to breathe sufficiently without assistance. Ventilators provide respiratory assistance to patients having a variety of contagious and non-contagious pulmonary disorders, such as pneumonia, ALS or Lou Gehrig's disease, post polio syndrome, head or neck injuries, chronic obstructive pulmonary diseases (asthma, bronchitis, emphysema, etc.), obstructive sleep apnea, congestive heart failure, and neuromuscular paralysis. Flow sensors (i.e., gas flow sensors) are often used in ventilators to ensure that an appropriate amount of gas is flowing to the patient. As can be expected, the types of flow sensors used in ventilators may be relatively costly given the fact that the operation of the potentially life-preserving equipment relies heavily upon knowing that an appropriate amount of gas is flowing to the patient and this, in turn, can depend upon the orientation of the equipment.